Display driving unit circuit, driving method, display driving circuit and display device

ABSTRACT

A display driving unit circuit, a driving method, a display driving circuit and a display device are provided. The display driving unit circuit includes a pixel driving circuit and a light-emission control signal generation circuit. The light-emission control signal generation circuit is coupled to the pixel driving circuit. The pixel driving circuit is to drive a pixel to emit light. The light-emission control signal generation circuit is to supply a display light-emission control signal to the pixel driving circuit at a display stage to enable the pixel in a displaying mode and supply a fingerprint detection light-emission control signal to the pixel driving circuit at a fingerprint detection stage to enable the pixel in a fingerprint detection light-emission mode at the fingerprint detection stage. The display stage and the fingerprint detection stage are different time periods.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No.201611079663.2 filed on Nov. 30, 2016, which is incorporated herein byreference in its entirety.

TECHNICAL FIELD

The present disclosure relates to the field of display drivingtechnology, in particular to a display driving unit circuit, a drivingmethod, a display driving circuit and a display device.

BACKGROUND

Recently, with the rapid development of technologies, display productshaving a fingerprint detection function gradually come into people'slives and work. Due to uniqueness of fingerprints, the fingerprintdetection technology has attracted much attention. Press-type andslide-type fingerprint recognition technologies on the basis of asilicon-based process have been integrated into a mobile product, and infuture the focus of attention will be on the fingerprint recognitiontechnology at a display region.

In a conventional photo sensor-based fingerprint detection unit, eachfingerprint sensor consists of one photosensitive diode and oneswitching thin film transistor (TFT). In scanning a fingerprint, lightbeams from a light source may be reflected differently due to adifference between a valley and a ridge of the fingerprint, so the lightintensity at the photosensitive diode may vary and thereby generatedifferent photocurrents. Under the control of the switching TFT, thecurrents flowing through the photosensitive diode may be readsequentially, thereby achieving the detecting of the valleys and ridgesof the fingerprint. However, the conventional fingerprint detection unitincludes a plurality of switching TFTs, and in case that the performanceof the switching TFT is deteriorated due to environmental facts, theswitching TFT may be turned on or off erroneously. As a result, thefingerprint detection effect may be adversely affected. In addition, dueto the switching TFTs, the aperture ratio of a display panel may beadversely affected.

SUMMARY

In one aspect, the present disclosure provides in some embodiments adisplay driving unit circuit, including a pixel driving circuit and alight-emission control signal generation circuit. The light-emissioncontrol signal generation circuit is coupled to the pixel drivingcircuit. The pixel driving circuit is configured to drive a pixel toemit light. The light-emission control signal generation circuit isconfigured to supply a display light-emission control signal to thepixel driving circuit at a display stage to enable the pixel in adisplaying mode and supply a fingerprint detection light-emissioncontrol signal to the pixel driving circuit at a fingerprint detectionstage to enable the pixel in a fingerprint detection light-emissionmode. The display stage and the fingerprint detection stage aredifferent time periods.

Further, the light emitted from the pixel in the displaying mode is of afirst frequency, the light emitted from the pixel in the fingerprintdetection light-emission mode is of a second frequency, and the firstfrequency is different from the second frequency.

Further, the fingerprint detection light-emission control signal is asquare-wave light-emission control signal having a frequency equal tothe second frequency. A cycle of the square-wave light-emission controlsignal includes a first time period in which the pixel driving circuitcontrols the pixel to emit light having a frequency equal to the firstfrequency under the control of the square-wave light-emission controlsignal and a second time period in which the pixel driving circuitcontrols the pixel to emit light having a frequency equal to the secondfrequency under the control of the square-wave light-emission controlsignal.

Further, the first frequency is substantially equal to 0 Hz, and thesecond frequency is greater than 1000 Hz.

Further, the display driving unit circuit further includes a voltagesignal generation circuit. The voltage signal generation circuit iscoupled to the light-emission control signal generation circuit and isconfigured to supply the fingerprint detection light-emission controlsignal to a light-emission control signal output end of thelight-emission control signal generation circuit at the fingerprintdetection stage.

Further, the voltage signal generation circuit includes a first startsignal input end, a first clock signal output end, a second clock signaloutput end, a first level output end, a second level output end, a thirdlevel output end and a voltage signal output end. The voltage signalgeneration circuit further includes: a first voltage control nodecontrol circuit that is coupled to the first start signal input end, thefirst clock signal output end, the second clock signal output end, thefirst level output end, the second level output end and a first voltagecontrol node, and is configured to enable a potential of the firstvoltage control node to be a first level and enable the potential of thefirst voltage control node to be a second level at the fingerprintdetection stage under the control of the first start signal input end,the first clock signal output end, the second clock signal output end,the first level output end and the second level output end; a secondvoltage control node control circuit that is coupled to the firstvoltage control node, the first clock signal output end, the secondclock signal output end, the first level output end, the second leveloutput end and a second voltage control node, and is configured toenable a potential of the second voltage control node to be the secondlevel and enable the potential of the second voltage control node to bethe first level at the fingerprint detection stage under the control ofthe first voltage control node, the first clock signal output end, thesecond clock signal output end, the first level output end and thesecond level output end; and a voltage signal generation circuit that iscoupled to the first voltage control node, the second voltage controlnode, the third level output end, the second level output end and avoltage signal output end, and is configured to enable the voltagesignal output end to receive a signal from the second level output endunder the control of the second voltage control node, and enable thevoltage signal output end to receive a signal from the third leveloutput end under the control of the first voltage control node at thefingerprint detection stage to enable the voltage signal output end tooutput the fingerprint detection light-emission control signal at thefingerprint detection stage.

Further, the first voltage control node control circuit includes: afirst voltage control transistor, a second voltage control transistor, athird voltage control transistor, a fourth voltage control transistor, afifth voltage control transistor, a sixth voltage control transistor, aseventh voltage control transistor, a first storage capacitor and asecond storage capacitor. A gate electrode of the first voltage controltransistor is coupled to the first clock signal output end, and a firstelectrode of the first voltage control transistor is coupled to thefirst start signal input end. A gate electrode of the second voltagecontrol transistor is coupled to a second electrode of the first voltagecontrol transistor, and a second electrode of the second voltage controltransistor is coupled to the first clock signal output end. A gateelectrode of the third voltage control transistor is coupled to thefirst clock signal output end, a first electrode of the third voltagecontrol transistor is coupled to a first electrode of the second voltagecontrol transistor, and a second electrode of the third voltage controltransistor is coupled to a low level output end. A gate electrode of thefourth voltage control transistor is coupled to the first electrode ofthe third voltage control transistor, a first electrode of the fourthvoltage control transistor is coupled to a high level output end, and asecond electrode of the fourth voltage control transistor is coupled tothe first voltage control node. A gate electrode of the fifth voltagecontrol transistor is coupled to the second electrode of the firstvoltage control transistor, a first electrode of the fifth voltagecontrol transistor is coupled to the first voltage control node, and asecond electrode of the fifth voltage control transistor is coupled tothe second clock signal input end. A gate electrode of the sixth voltagecontrol transistor is coupled to the gate electrode of the fourthvoltage control transistor, and a first electrode of the sixth voltagecontrol transistor is coupled to a high level output end. A gateelectrode of the seventh voltage control transistor is coupled to thesecond clock signal output end, a first electrode of the seventh voltagecontrol transistor is coupled to a second electrode of the sixth voltagecontrol transistor, and a second electrode of the seventh voltagecontrol transistor is coupled to the gate electrode of the fifth voltagecontrol transistor. A first end of the first storage capacitor iscoupled to the gate electrode of the fifth voltage control transistor,and a second end of the first storage capacitor is coupled to the firstvoltage control node. A first end of the second storage capacitor iscoupled to the gate electrode of the fourth voltage control transistor,and a second end of the second storage capacitor is coupled to the highlevel output end.

Further, the second voltage control node control circuit includes: aneighth voltage control transistor, a ninth voltage control transistorand a third storage capacitor. A gate electrode of the eighth voltagecontrol transistor is coupled to the first voltage control node, a firstelectrode of the eighth voltage control transistor is coupled to thehigh level output end, and a second electrode of the eighth voltagecontrol transistor is coupled to the second voltage control node. A gateelectrode of the ninth voltage control transistor is coupled to thefirst clock signal output end, a first electrode of the ninth voltagecontrol transistor is coupled to the second voltage control node, and asecond electrode of the ninth voltage control transistor is coupled tothe low level output end. A first end of the third storage capacitor iscoupled to the second voltage control node, and a second end of thethird storage capacitor is coupled to the second clock signal outputend.

Further, the voltage signal generation circuit includes: a first voltagesignal generation transistor and a second voltage signal generationtransistor. A gate electrode of the first voltage signal generationtransistor is coupled to the first voltage control node, a firstelectrode of the first voltage signal generation transistor is coupledto a square-wave voltage signal output end, and a second electrode ofthe first voltage signal generation transistor is coupled to the voltagesignal output end. A gate electrode of the second voltage signalgeneration transistor is coupled to the second voltage control node, afirst electrode of the second voltage signal generation transistor iscoupled to the voltage signal output end, and a second electrode of thesecond voltage signal generation transistor is coupled to the low leveloutput end.

Further, the light-emission control signal generation circuit includes asecond start signal input end, a first clock signal output end, a secondclock signal output end, a first level output end, a second level outputend, a voltage signal output end and a light-emission control signaloutput end. The light-emission control signal generation circuit furtherincludes: a first light-emission control node control circuit that iscoupled to the second start signal input end, the first clock signaloutput end, the second clock signal output end, the first level outputend, the second level output end and a first light-emission controlnode, and is configured to enable a potential of the firstlight-emission control node to be a first level at the fingerprintdetection stage and enable the potential of the first light-emissioncontrol node to be a second level at a light-emission stage under thecontrol of the second start signal input end, the first clock signaloutput end, the second clock signal output end, the first level outputend and the second level output end; a second light-emission controlnode control circuit that is coupled to the first light-emission controlnode, the first clock signal output end, the second clock signal outputend, the first level output end, the second level output end and asecond light-emission control node, and is configured to enable apotential of the second light-emission control node to be the secondlevel at the fingerprint detection stage and enable the potential of thesecond light-emission control node to be the first level at thelight-emission stage under the control of the first light-emissioncontrol node, the first clock signal output end, the second clock signaloutput end, the first level output end and the second level output end;and a light-emission control signal generation circuit that is coupledto the first light-emission control node, the second light-emissioncontrol node, the first level output end, the voltage signal output endand the light-emission control signal output end, and is configured toenable the light-emission control signal output end to receive a signalfrom the first level output end under the control of the firstlight-emission control node at the light-emission stage, and enable thelight-emission control signal output end to receive a signal from thevoltage signal output end under the control of the second light-emissioncontrol node at the fingerprint detection stage to enable thelight-emission control signal output end to output the fingerprintdetection light-emission control signal at the fingerprint detectionstage.

Further, the first light-emission control node control circuit includes:a first light-emission control transistor, a second light-emissioncontrol transistor, a third light-emission control transistor, a fourthlight-emission control transistor, a fifth light-emission controltransistor, a sixth light-emission control transistor, a seventhlight-emission control transistor, a first capacitor and a secondcapacitor. A gate electrode of the first light-emission controltransistor is coupled to the first clock signal output end, and a firstelectrode of the first light-emission control transistor is coupled tothe second start signal input end. A gate electrode of the secondlight-emission control transistor is coupled to a second electrode ofthe first light-emission control transistor, and a second electrode ofthe second light-emission control transistor is coupled to the firstclock signal output end. A gate electrode of the third light-emissioncontrol transistor is coupled to the first clock signal output end, afirst electrode of the third light-emission control transistor iscoupled to a first electrode of the second light-emission controltransistor, and a second electrode of the third light-emission controltransistor is coupled to the low level output end. A gate electrode ofthe fourth light-emission control transistor is coupled to the firstelectrode of the third light-emission control transistor, a firstelectrode of the fourth light-emission control transistor is coupled tothe high level output end, and a second electrode of the fourthlight-emission control transistor is coupled to a first light-emissioncontrol node. A gate electrode of the fifth light-emission controltransistor is coupled to the second electrode of the firstlight-emission control transistor, a first electrode of the fifthlight-emission control transistor is coupled to the first light-emissioncontrol node, and a second electrode of the fifth light-emission controltransistor is coupled to the second clock signal output end. A gateelectrode of the sixth light-emission control transistor is coupled tothe gate electrode of the fourth light-emission control transistor, anda first electrode of the sixth light-emission control transistor iscoupled to the high level output end. A gate electrode of the seventhlight-emission control transistor is coupled to the second clock signaloutput end, a first electrode of the seventh light-emission controltransistor is coupled to a second electrode of the sixth light-emissioncontrol transistor, and a second electrode of the seventh light-emissioncontrol transistor is coupled to the gate electrode of the fifthlight-emission control transistor. A first end of the first capacitor iscoupled to the gate electrode of the fifth light-emission controltransistor, and a second end of the first capacitor is coupled to thefirst light-emission control node. A first end of the second capacitoris coupled to the gate electrode of the fourth light-emission controltransistor, and a second end of the second capacitor is coupled to thehigh level output end.

Further, the second light-emission control node control circuitincludes: an eighth light-emission control transistor, a ninthlight-emission control transistor and a third capacitor. A gateelectrode of the eighth light-emission control transistor is coupled tothe first light-emission control node, a first electrode of the eighthlight-emission control transistor is coupled to the high level outputend, and a second electrode of the eighth light-emission controltransistor is coupled to the second light-emission control node. A gateelectrode of the ninth light-emission control transistor is coupled tothe first clock signal output end, a first electrode of the ninthlight-emission control transistor is coupled to a second light-emissioncontrol node, and a second electrode of the ninth light-emission controltransistor is coupled to the low level output end. A first end of thethird capacitor is coupled to the second light-emission control node,and a second end of the third capacitor is coupled to the second clocksignal output end.

Further, the light-emission control signal generation circuit includes:a first light-emission control signal generation transistor and a secondlight-emission control signal generation transistor. A gate electrode ofthe first light-emission control signal generation transistor is coupledto the first light-emission control node, a first electrode of the firstlight-emission control signal generation transistor is coupled to thehigh level output end, and a second electrode of the firstlight-emission control signal generation transistor is coupled to thelight-emission control signal output. A gate electrode of the secondlight-emission control signal generation transistor is coupled to thesecond light-emission control node, a first electrode of the secondlight-emission control signal generation transistor is coupled to thelight-emission control signal output end, and a second electrode of thesecond light-emission control signal generation transistor is coupled tothe voltage signal output end.

Further, the pixel driving circuit includes: a first transistor, asecond transistor, a third transistor, a fourth transistor, a fifthtransistor, a sixth transistor and a storage capacitor. A gate electrodeof the first transistor is coupled to a resetting end, a sourceelectrode of the first transistor is coupled to a resetting voltagesignal input end, and a drain electrode of the first transistor iscoupled to a first end of the storage capacitor. A gate electrode of thesecond transistor is coupled to a corresponding gate line, and a sourceelectrode of the second transistor is coupled to the first end of thestorage capacitor. A gate electrode of the third transistor is coupledto the first end of the storage capacitor, and a source electrode of thethird transistor is coupled to a drain electrode of the secondtransistor. A gate electrode of the fourth transistor is coupled to acorresponding gate line, a source electrode of the fourth transistor iscoupled to a corresponding data line, and a drain electrode of thefourth transistor is coupled to a second end of the storage capacitor. Agate electrode of the fifth transistor is coupled to a control signalinput end, and a source electrode of the fifth transistor is coupled tothe second end of the storage capacitor. A gate electrode of the sixthtransistor is coupled to the light-emission control signal input end, asource electrode of the sixth transistor is coupled to an anode of anorganic light-emitting diode, and a drain electrode of the sixthtransistor is coupled to the source electrode of the third transistor.

In another aspect, the present disclosure provides in some embodiments amethod of driving the above-mentioned display driving unit circuit,including steps of: supplying, by a light-emission control signalgeneration circuit, a display light-emission control signal to a pixeldriving circuit at a display stage to enable a pixel in a displayingmode; and supplying, by the light-emission control signal generationcircuit, a fingerprint detection light-emission control signal to thepixel driving circuit at a fingerprint detection stage to control thepixel driving circuit at the fingerprint detection stage to enable thepixel in a fingerprint detection light-emission mode.

Further, the fingerprint detection light-emission control signal is asquare-wave light-emission control signal having a frequency greaterthan 1000 Hz. A cycle of the square-wave light-emission control signalincludes a first time period in which the pixel driving circuit controlsthe pixel to emit light having a frequency equal to 0 Hz under thecontrol of the square-wave light-emission control signal and a secondtime period in which the pixel driving circuit controls the pixel toemit light having a frequency greater than 1000 Hz under the control ofthe square-wave light-emission control signal.

In yet another aspect, the present disclosure provides in someembodiments a display driving circuit including a plurality oflight-emission control lines and a plurality of display driving unitcircuits. Each of the plurality of display driving unit circuit includesa pixel driving circuit and a light-emission control signal generationcircuit. The light-emission control signal generation circuit is coupledto a light-emission control signal input end of the pixel drivingcircuit and is configured to supply a display light-emission controlsignal to the pixel driving circuit at a display stage to enable a pixelin a displaying mode and supply a fingerprint detection light-emissioncontrol signal to the pixel driving circuit at a fingerprint detectionstage to enable the pixel in a fingerprint detection light-emissionmode. Each of the plurality of light-emission control lines is coupledto a light-emission control signal output end of one pixel drivingcircuit of the plurality of display driving unit circuits. Displaystages for different rows of pixels do not overlap each other, andfingerprint detection stages for different rows of pixels do not overlapeach other.

In still yet another aspect, the present disclosure provides in someembodiments a display device including the above-mentioned displaydriving circuit and photovoltaic conversion elements. Each photovoltaicconversion element is arranged at a position corresponding to anon-light-emission region, coupled to a fingerprint current read line,and configured to convert a received optical signal into a fingerprintcurrent signal and output the fingerprint current signal via thefingerprint current read line.

Further, each of the photovoltaic conversion elements is between twoadjacent pixels in a row direction.

Further, each photovoltaic conversion element includes a photo diodehaving an anode coupled to a fixed electrically-conductive electrode anda cathode coupled to the fingerprint current read line.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing a display driving unit circuitaccording to some embodiments of the present disclosure;

FIG. 2 is a circuit diagram of a pixel driving circuit of the displaydriving unit circuit according to some embodiments of the presentdisclosure;

FIG. 3 is a schematic view showing a voltage signal generation circuitof the display driving unit circuit according to some embodiments of thepresent disclosure;

FIG. 4 is a timing diagram of the voltage signal generation circuit inFIG. 3;

FIG. 5 is another circuit diagram of the voltage signal generationcircuit of the display driving unit circuit according to someembodiments of the present disclosure;

FIG. 6 is a circuit diagram of a light-emission control signalgeneration circuit of the display driving unit circuit according to someembodiments of the present disclosure;

FIG. 7 is a timing diagram of the light-emission control signalgeneration circuit of the display driving unit circuit according to someembodiments of the present disclosure;

FIG. 8 is a planar view showing photosensitive PIN junctions arrangedbetween pixels according to some embodiments of the present disclosure;and

FIG. 9 is a schematic view showing the photosensitive PIN junctionsarranged on a glass encapsulation substrate at positions correspondingnon-light-emission regions according to some embodiments of the presentdisclosure.

DETAILED DESCRIPTION

In order to make the objects, the technical solutions and the advantagesof the present disclosure clear and complete, the present disclosurewill be described hereinafter in a clear and complete manner inconjunction with the drawings and embodiments. Evidently, the followingembodiments merely relate to a part of, rather than all of, theembodiments of the present disclosure, and based on these embodiments, aperson skilled in the art may, without any creative effort, obtain otherembodiments, which also fall within the scope of the present disclosure.

As shown in FIG. 1, the present disclosure provides in some embodimentsa display driving unit circuit, which includes a pixel driving circuit10 configured to drive a pixel to emit light and a light-emissioncontrol signal generation circuit 11. The light-emission control signalgeneration circuit 11 is coupled to a light-emission control signalinput end EMIN of the pixel driving circuit 10 and configured to, at adisplay stage, supply a display light-emission control signal to thepixel driving circuit 10 and, at a fingerprint detection stage, supply afingerprint detection light-emission control signal to the pixel drivingcircuit 10 to control the pixel driving circuit 10 to enable the pixelto emit light in a fingerprint detection light-emission mode at thefingerprint detection stage. The display stage and the fingerprintdetection stage are different time periods.

As shown in FIG. 8 and FIG. 9, the display driving unit circuit furtherincludes photovoltaic conversion elements 95. The photovoltaicconversion elements 95 may be provided to detect a fingerprint. Eachphotovoltaic conversion element 95 may be arranged at a positioncorresponding to a non-light-emission region 96 and between two adjacentpixels in the row, coupled to a fingerprint current read line, andconfigured to convert a received optical signal into a correspondingfingerprint current signal which is then outputted via the fingerprintcurrent read line. In one embodiment shown in FIG. 8 and FIG. 9, thephotovoltaic conversion element 95 may include a photo diode, forexample, a photosensitive PIN junction may be arranged between twoadjacent pixels.

According to the display driving unit circuit in the embodiments of thepresent disclosure, the light-emission control signal generation circuitsupplies the fingerprint detection light-emission control signal to thecorresponding pixel driving circuit at the fingerprint detection stage,and the photovoltaic conversion element outputs a photocurrent signal atthe fingerprint detection stage, so as to perform the fingerprintdetection. As a result, it is possible for the display driving unitcircuit in the embodiments of the present disclosure to perform thefingerprint detection without any additional switching transistor,thereby improving the accuracy of the fingerprint detection as well asthe aperture ratio of the display panel.

In practice, there may be a plurality of photovoltaic conversionelements each arranged between two adjacent pixels in the row.Alternatively, the photovoltaic conversion elements may be arranged atintervals based on the requirement on the fingerprint detectionaccuracy.

In implementations, the photovoltaic conversion element may benontransparent, so it may be arranged at a position corresponding to thenon-light-emission region so as not to adversely affect the normaldisplay.

For the display driving unit circuit in FIG. 1, at the fingerprintdetection stage, the light-emission control signal generation circuit 11supplies the fingerprint detection light-emission control signal to thepixel driving circuit 10 to control the pixel driving circuit 10 toenable the pixel to emit light in the fingerprint detectionlight-emission mode to enable the light from the pixel not to beperceived by human eyes at the fingerprint detection stage (e.g., thefingerprint detection light-emission control signal may be ahigh-frequency square-wave light-emission control signal so that thelight form the pixel may not be perceived by the human eyes at thefingerprint detection stage). In addition, light emitted by alight-emitting element of each pixel in the row (e.g., an OrganicLight-Emitting Diode (OLED)) at the fingerprint detection stage isdifferent from light emitted by the light-emitting element of each pixelin the row at the display stage. For example, at the display stage thelight-emitting element of each pixel in the row may emit light stablyand continuously (i.e., displaying mode), while at the fingerprintdetection stage an optical signal received by the photovoltaicconversion element may be a high-frequency modulated optical signal, sothat the photovoltaic conversion element may convert the receivedhigh-frequency modulated optical signal into a high-frequency modulatedelectric signal. Then, the high-frequency modulated optical signal maybe demodulated through an Integrated Circuit (IC), so as to acquire asignal carrying fingerprint information.

For example, in one embodiment, the light emitted from the pixel in thedisplaying mode is of a first frequency, the light emitted from thepixel in the fingerprint detection light-emission mode is of a secondfrequency, and the first frequency is different from the secondfrequency. Further, the first frequency is less than the secondfrequency. The first frequency is a frequency of light when the pixelemits light stably and continuously, and the second frequency is afrequency of light when the light from the pixel may not be perceived bythe human eyes at the fingerprint detection stage. In one embodiment,the first frequency is substantially equal to 0 Hz, and the secondfrequency is greater than 1000 Hz.

In practice, as shown in FIG. 8, the photovoltaic conversion element maybe a photo diode, and a photosensitive PIN junction may be arrangedbetween two adjacent pixels. Through supplying the light-emissioncontrol signal line by line, the fingerprint current read line mayreceive PIN light response signals with respect to the light from thepixels in different rows.

In a possible embodiment of the present disclosure, the fingerprintdetection light-emission control signal may be a square-wavelight-emission control signal having a frequency greater than 1000 Hz.In this way, the light from the pixel in the corresponding row may notbe perceived by the human eyes at the fingerprint detection stage, so asto prevent the normal display from being adversely affected. Inaddition, at the fingerprint detection stage, the optical signal fromeach pixel is a square-wave modulated optical signal, the photovoltaicconversion element may convert the square-wave modulated optical signalinto a square-wave modulated fingerprint current, so it is possible todifferentiate the current acquired through the conversion ofphotovoltaic conversion element from a fingerprint current.

A cycle of the square-wave light-emission control signal includes afirst time period in which the pixel driving circuit controls the row ofpixels to emit light under the control of the square-wave light-emissioncontrol signal and a second time period in which the pixel drivingcircuit controls the pixel not to emit light under the control of thesquare-wave light-emission control signal.

For example, as shown in FIG. 2, an example of the pixel driving circuit10 includes a light-emission control signal input end EMIN, a controlsignal input end Ctrl, a resetting end Reset, a resetting voltage signalinput end for inputting a resetting voltage signal Vinit, a firsttransistor T1, a second transistor T2, a third transistor T3, a fourthtransistor T4, a fifth transistor T5, a sixth transistor T6 and astorage capacitor C1.

A gate electrode of T1 is coupled to the resetting end Reset, a sourceelectrode thereof is coupled to the resetting voltage signal input endfor inputting a resetting voltage signal Vinit, and a drain electrodethereof is coupled to a first end of the storage capacitor C1.

A gate electrode of T2 is coupled to a corresponding gate line Gate, anda source electrode thereof is coupled to the first end of the storagecapacitor C1.

A gate electrode of T3 is coupled to the first end of the storagecapacitor C1, and a source electrode thereof is coupled to a drainelectrode of T2.

A gate electrode of T4 is coupled to a corresponding gate line Gate, asource electrode thereof is coupled to a corresponding data line Data,and a drain electrode thereof is coupled to a second end of the storagecapacitor C1.

A gate electrode of T5 is coupled to the control signal input end Ctrl,and a source electrode thereof is coupled to the second end of thestorage capacitor C1.

A gate electrode of T6 is coupled to the light-emission control signalinput end EMIN, a source electrode thereof is coupled to an anode of anOLED, and a drain electrode thereof is coupled to the source electrodeof T3.

In FIG. 2, ELVDD represents a high level, and ELVSS represents a lowlevel.

In FIG. 2, T6 is an n-type transistor. At this time, at the displaystage for the pixel in a corresponding row, a light-emission controlsignal EM from the light-emission control signal input end EMIN is of ahigh level, so OLED may emit light. At the fingerprint detection stagefor the pixel in a corresponding row, EM is a square-wave light-emissioncontrol signal. In case that the square-wave light-emission controlsignal is at a high level, OLED may emit light, and in case that thesquare-wave light-emission control signal is at a low level, OLED maynot emit light.

In practice, as shown in FIG. 2A, T6 may also be a p-type transistor. Atthe display stage for the pixel in a corresponding row, EM is at a lowlevel, so OLED may emit light. At the fingerprint detection stage forthe pixel in a corresponding row, EM is a square-wave light-emissioncontrol signal. In case that the square-wave light-emission controlsignal is at a low level, OLED may emit light, and in case that thesquare-wave light-emission control signal is at a high level, OLED maynot emit light.

In a possible embodiment of the present disclosure, the display drivingunit circuit further includes a voltage signal generation circuitcoupled to the light-emission control signal generation circuit andconfigured to supply the fingerprint detection light-emission controlsignal to a light-emission control signal output end of thelight-emission control signal generation circuit at the fingerprintdetection stage.

In a display driving unit circuit in the related art, a low level outputend coupled to a pull-down transistor of the light-emission controlsignal generation circuit may output a low level within all timeperiods. However, in order to enable the light-emission control signalgeneration circuit to output the fingerprint detection light-emissioncontrol signal at the fingerprint detection stage for the pixel in acorresponding row, the display driving unit circuit in the embodimentsof the present disclosure may include the voltage signal generationcircuit, so as to supply the fingerprint detection light-emissioncontrol signal to the light-emission control signal generation circuitat the fingerprint detection stage.

In a possible embodiment of the present disclosure, the voltage signalgeneration circuit includes a first start signal input end, a firstclock signal output end, a second clock signal output end, a first leveloutput end, a second level output end, a third level output end and avoltage signal output end. The voltage signal generation circuit furtherincludes: a first voltage control node control circuit, a second voltagecontrol node control circuit and a voltage signal generation circuit.

The first voltage control node control circuit is coupled to the firststart signal input end, the first clock signal output end, the secondclock signal output end, the first level output end, the second leveloutput end and a first voltage control node. The first voltage controlnode control circuit is to enable a potential of the first voltagecontrol node to be a first level at a first start stage and enable thepotential of the first voltage control node to be a second level at thefingerprint detection stage under the control of a first start signal, afirst clock signal, a second clock signal, the first level and thesecond level.

The second voltage control node control circuit is coupled to the firstvoltage control node, the first clock signal output end, the secondclock signal output end, the first level output end, the second leveloutput end and a second voltage control node. The second voltage controlnode control circuit is to enable a potential of the second voltagecontrol node to be the second level at the first start stage and enablethe potential of the second voltage control node to be the first levelat the fingerprint detection stage under the control of the firstvoltage control node, the first clock signal, the second clock signal,the first level and the second level.

The voltage signal generation circuit is coupled to the first voltagecontrol node, the second voltage control node, the third level outputend, the second level output end and a voltage signal output end. Thevoltage signal generation circuit is to enable the voltage signal outputend to be coupled to the second level output end under the control ofthe second voltage control node at the first start stage, and enable thevoltage signal output end to be coupled to the third level output endunder the control of the first voltage control node at the fingerprintdetection stage, so as to enable the voltage signal output end to outputthe fingerprint detection light-emission control signal at thefingerprint detection stage, thereby enabling the pixels to emit lightrow by row.

As show in FIG. 3, the voltage signal generation circuit includes afirst start signal input end STV1, a first clock signal output end CK1,a second clock signal output end CK2, a high level output end foroutputting a high level VGH, a low level output end for outputting a lowlevel VGL, a square-wave voltage signal output end for outputting asquare-wave voltage signal VGH-A, and a voltage signal output end foroutputting a voltage signal VGL-1.

The voltage signal generation circuit further includes: a first voltagecontrol node control circuit 31, a second voltage control node controlcircuit 32 and a voltage signal generation circuit 33.

The first voltage control node control circuit 31 is coupled to thefirst start signal input end STV1, the first clock signal output endCK1, the second clock signal output end CK2, the high level output endfor outputting the high level VGH, the low level output end foroutputting the low level VGL and a first voltage control node GO. Thefirst voltage control node control circuit 31 is to enable a potentialof the first voltage control node GO to be a high level at a first startstage TS1 and enable the potential of the first voltage control node GOto be a low level at the fingerprint detection stage TF under thecontrol of a first start signal inputted by STV1, a first clock signaloutputted by CK1, a second clock signal outputted by CK2, the high levelVGH and the low level VGL (FIG. 4 shows a timing diagram of thepotential of GO).

The second voltage control node control circuit 32 is coupled to thefirst voltage control node GO, the first clock signal output end CK1,the second clock signal output end CK2, the high level output end foroutputting the high level VGH, the low level output end for outputtingthe low level VGL and a second voltage control node GE. The secondvoltage control node control circuit 32 is to enable a potential of thesecond voltage control node GE to be a low level at the first startstage TS1 and enable the potential of the second voltage control node GEto be a high level at the fingerprint detection stage TF under thecontrol of the first voltage control node GO, the first clock signaloutputted by CK1, the second clock signal outputted by CK2, the highlevel VGH and the low level VGL.

The voltage signal generation circuit 33 is coupled to the first voltagecontrol node GO, the second voltage control node GE, the square-wavevoltage signal output end for outputting the square-wave voltage signalVGH-A, the low level output end for outputting the low level VGL and thevoltage signal output end for outputting the voltage signal VGL-1. Thevoltage signal generation circuit 33 is to enable the voltage signaloutput end to be electrically coupled to the low level output end underthe control of the second voltage control node GE at the first startstage TS1, and enable the voltage signal output end to be electricallycoupled to the third level output end under the control of the firstvoltage control node GO at the fingerprint detection stage to enable thevoltage signal output end to output the fingerprint detectionlight-emission control signal at the fingerprint detection stage.

In practice, as shown in FIG. 4, the square-wave voltage signal VGH-A isacquired by superposing a square-wave level signal to the original highlevel VGH.

As shown in FIG. 4, during the operation of the voltage signalgeneration circuit in FIG. 3, at the first start stage TS1, STV1 and CK1each output a low level, CK2 outputs a high level, the first voltagecontrol node control circuit 31 controls the potential of GO to be ahigh level, the second voltage control node control circuit 32 controlsthe potential of GE to be a low level, and the voltage signal generationcircuit 33 controls the voltage signal output end to be electricallycoupled to the low level output end, so VGL-1 is a low level. At thefingerprint detection stage TF, STV1 and CK1 each output a high level,CK2 outputs a low level, the first voltage control node control circuit31 controls the potential of GO to be a low level, the second voltagecontrol node control circuit 32 controls the potential of GE to be ahigh level, and the voltage signal generation circuit 33 controls thevoltage signal output end to receive VGH-A, so VGL-1 is a square-wavevoltage signal.

As shown in FIG. 5, in a specific embodiment of the present disclosure,the first voltage control node control circuit includes: a first voltagecontrol transistor T1, a second voltage control transistor T2, a thirdvoltage control transistor T3, a fourth voltage control transistor T4, afifth voltage control transistor T5, a sixth voltage control transistorT6, a seventh voltage control transistor T7, a first storage capacitorC1 and a second storage capacitor C2.

A gate electrode of the first voltage control transistor T1 is coupledto the first clock signal output end CK1, and a first electrode of thefirst voltage control transistor T1 is coupled to the first start signalinput end STV1.

A gate electrode of the second voltage control transistor T2 is coupledto a second electrode of the first voltage control transistor T1, and asecond electrode of the second voltage control transistor T2 is coupledto the first clock signal output end CK1.

A gate electrode of the third voltage control transistor T3 is coupledto the first clock signal output end CK1, a first electrode of the thirdvoltage control transistor T3 is coupled to a first electrode of thesecond voltage control transistor T2, and a second electrode of thethird voltage control transistor T3 is coupled to the low level outputend for outputting the low level VGL.

A gate electrode of the fourth voltage control transistor T4 is coupledto the first electrode of the third voltage control transistor T3, afirst electrode of the fourth voltage control transistor T4 is coupledto the high level output end for outputting the high level VGH, and asecond electrode of the fourth voltage control transistor T4 is coupledto the first voltage control node GO.

A gate electrode of the fifth voltage control transistor T5 is coupledto the second electrode of the first voltage control transistor T1, afirst electrode of the fifth voltage control transistor T5 is coupled tothe first voltage control node GO, and a second electrode of the fifthvoltage control transistor T5 is coupled to the second clock signalinput end CK2.

A gate electrode of the sixth voltage control transistor T6 is coupledto the gate electrode of the fourth voltage control transistor T4, and afirst electrode of the sixth voltage control transistor T6 is coupled tothe high level output end for outputting the high level VGH.

A gate electrode of the seventh voltage control transistor T7 is coupledto the second clock signal output end CK2, a first electrode of theseventh voltage control transistor T7 is coupled to a second electrodeof the sixth voltage control transistor T6, and a second electrode ofthe seventh voltage control transistor T7 is coupled to the gateelectrode of the fifth voltage control transistor T5.

A first end of the first storage capacitor C1 is coupled to the gateelectrode of the fifth voltage control transistor T5, and a second endof the first storage capacitor C1 is coupled to the first voltagecontrol node GO.

A first end of the second storage capacitor C2 is coupled to the gateelectrode of the fourth voltage control transistor T4, and a second endof the second storage capacitor C2 is coupled to the high level outputend for outputting the high level VGH.

The second voltage control node control circuit includes: an eighthvoltage control transistor T8, a ninth voltage control transistor T9,and a third storage capacitor C3.

A gate electrode of the eighth voltage control transistor T8 is coupledto the first voltage control node GO, a first electrode of the eighthvoltage control transistor T8 is coupled to the high level output endfor outputting the high level VGH, and a second electrode of the eighthvoltage control transistor T8 is coupled to the second voltage controlnode GE.

A gate electrode of the ninth voltage control transistor T9 is coupledto the first clock signal output end CK1, a first electrode of the ninthvoltage control transistor T9 is coupled to the second voltage controlnode GE, and a second electrode of the ninth voltage control transistorT9 is coupled to the low level output end for outputting the low levelVGL.

A first end of the third storage capacitor C3 is coupled to the secondvoltage control node GE, and a second end of the third storage capacitorC3 is coupled to the second clock signal output end CK2.

The voltage signal generation circuit includes: a first voltage signalgeneration transistor T10 and a second voltage signal generationtransistor T11.

A gate electrode of the first voltage signal generation transistor T10is coupled to the first voltage control node GO, a first electrode ofthe first voltage signal generation transistor T10 is coupled to thesquare-wave voltage signal output end for outputting the square-wavevoltage signal VGH-A, and a second electrode of the first voltage signalgeneration transistor T10 is coupled to the voltage signal output endfor outputting the voltage signal VGL-1.

A gate electrode of the second voltage signal generation transistor T11is coupled to the second voltage control node GE, a first electrode ofthe second voltage signal generation transistor T11 is coupled to thevoltage signal output end VGL-1, and a second electrode of the secondvoltage signal generation transistor T11 is coupled to the low leveloutput end for outputting the low level VGL.

In FIG. 5, all the transistors are p-type transistors. In case that thefirst electrode is a drain electrode, the second electrode is a sourceelectrode, and in case that the first electrode is a source electrode,the second electrode is a drain electrode. In practice, the transistorsin FIG. 5 may also be n-type transistors (i.e., the types of thetransistors will not be particularly defined herein), and then, it ismerely necessary to change levels of the corresponding control signals.

As shown in FIG. 4, during the operation of the voltage signalgeneration circuit in FIG. 5, at the first start stage TS1, STV1 and CK1each output a low level and CK2 outputs a high level, so T3 and T1 areturned on, so as to enable STV1 to be coupled to the gate electrode ofT2 and the gate electrode of T5, thereby to write VGL into the gateelectrode of T4 and turn on T2 and T5. T4 is turned on, and thepotential of GO is at a high level. T10 is turned off, and T9 is turnedon under the control of CK1, so as to enable the potential of GE to beat a low level and turn on T11, thereby to enable VGL-1 to be at a lowlevel. At the fingerprint detection stage TF, STV1 and CK1 each output ahigh level, and CK2 outputs a low level, so T1, T3 and T9 are turnedoff, and a potential of the gate electrode of T5 is maintained as a lowlevel. GO is coupled to CK2, the potential of GO is at a low level, andT8 is turned on, so the potential of GE is at a high level. T11 isturned off, and T10 is turned on, so as to enable the voltage signaloutput end to receive VGH-A, thereby to enable VGL-1 to be a square-wavevoltage signal. As shown in FIG. 4, in stages other than the fingerprintdetection stage TF, VGL-1 is at a low level.

During the operation of the voltage signal generation circuit in FIG. 5,VGL may be at a low level all the time (not shown FIG. 4), and at thefingerprint detection stage TF, VGL-1 is a square-wave voltage signal,i.e., VGL is different from VGL-1. In practice, the potential of VGL mayalso be identical to that of VGL-1.

To be specific, the light-emission control signal generation circuitincludes a second start signal input end, a first clock signal outputend, a second clock signal output end, a first level output end, asecond level output end, a voltage signal output end and alight-emission control signal output end. The light-emission controlsignal generation circuit further includes a first light-emissioncontrol node control circuit, a second light-emission control nodecontrol circuit and a light-emission control signal generation circuit.

The first light-emission control node control circuit is coupled to thesecond start signal input end, the first clock signal output end, thesecond clock signal output end, the first level output end, the secondlevel output end and a first light-emission control node. The firstlight-emission control node control circuit is to enable a potential ofthe first light-emission control node to be a first level at a secondstart stage and the fingerprint detection stage and enable the potentialof the first light-emission control node to be a second level at alight-emission stage under the control of a second start signal, a firstclock signal, a second clock signal, the first level and the secondlevel.

The second light-emission control node control circuit is coupled to thefirst light-emission control node, the first clock signal output end,the second clock signal output end, the first level output end, thesecond level output end and a second light-emission control node. Thesecond light-emission control node control circuit is configured toenable a potential of the second light-emission control node to be thesecond level at the second start stage and the fingerprint detectionstage and enable the potential of the second light-emission control nodeto be the first level at the light-emission stage under the control ofthe first light-emission control node, the first clock signal, thesecond clock signal, the first level and the second level.

The light-emission control signal generation circuit is coupled to thefirst light-emission control node, the second light-emission controlnode, the first level output end, the voltage signal output end and thelight-emission control signal output end. The light-emission controlsignal generation circuit is to enable the light-emission control signaloutput end to be coupled to the first level output end under the controlof the first light-emission control node at the light-emission stage,and enable the light-emission control signal output end to be coupled tothe voltage signal output end under the control of the secondlight-emission control node at the fingerprint detection stage, so as toenable the light-emission control signal output end to output thefingerprint detection light-emission control signal at the fingerprintdetection stage.

In practice, the voltage signal generation circuit may be of a structureidentical to the light-emission control signal generation circuit,merely with differences in the timing of the control signals. In apossible embodiment of the present disclosure, the voltage signalgeneration circuit may also be of a structure different from thelight-emission control signal generation circuit.

As shown in FIG. 6, in a specific embodiment of the present disclosure,the first light-emission control node control circuit includes: a firstlight-emission control transistor T61, a second light-emission controltransistor T62, a third light-emission control transistor T63, a fourthlight-emission control transistor T64, a fifth light-emission controltransistor T65, a sixth light-emission control transistor T66, a seventhlight-emission control transistor T67, a first capacitor Cs1 and asecond capacitor Cs2.

A gate electrode of the first light-emission control transistor T61 iscoupled to the first clock signal output end CK1, and a first electrodeof the first light-emission control transistor T61 is coupled to thesecond start signal input end STV2.

A gate electrode of the second light-emission control transistor T62 iscoupled to a second electrode of the first light-emission controltransistor T61, and a second electrode of the second light-emissioncontrol transistor T62 is coupled to the first clock signal output endCK1.

A gate electrode of the third light-emission control transistor T63 iscoupled to the first clock signal output end CK1, a first electrode ofthe third light-emission control transistor T63 is coupled to a firstelectrode of the second light-emission control transistor T62, and asecond electrode of the third light-emission control transistor T63 iscoupled to the low level output end for outputting the low level VGL.

A gate electrode of the fourth light-emission control transistor T64 iscoupled to the first electrode of the third light-emission controltransistor T63, a first electrode of the fourth light-emission controltransistor T64 is coupled to the high level output end for outputtingthe high level VGH, and a second electrode of the fourth light-emissioncontrol transistor T64 is coupled to a first light-emission control nodeEC1.

A gate electrode of the fifth light-emission control transistor T65 iscoupled to the second electrode of the first light-emission controltransistor T61, a first electrode of the fifth light-emission controltransistor T65 is coupled to the first light-emission control node EC1,and a second electrode of the fifth light-emission control transistorT65 is coupled to the second clock signal output end CK2.

A gate electrode of sixth light-emission control transistor T66 iscoupled to the gate electrode of the fourth light-emission controltransistor T64, and a first electrode of the sixth light-emissioncontrol transistor T66 is coupled to the high level output end foroutputting the high level VGH.

A gate electrode of the seventh light-emission control transistor T67 iscoupled to the second clock signal output end CK2, a first electrode ofthe seventh light-emission control transistor T67 is coupled to a secondelectrode of the sixth light-emission control transistor T66, and asecond electrode of the seventh light-emission control transistor T67 iscoupled to the gate electrode of the fifth light-emission controltransistor T65.

A first end of the first capacitor Cs1 is coupled to the gate electrodeof the fifth light-emission control transistor T65, and a second end ofthe first capacitor Cs1 is coupled to the first light-emission controlnode EC1.

A first end of the second capacitor Cs2 is coupled to the gate electrodeof the fourth light-emission control transistor T64, and a second end ofthe second capacitor Cs2 is coupled to the high level output end foroutputting the high level VGH.

The second light-emission control node control circuit includes: aneighth light-emission control transistor T68, a ninth light-emissioncontrol transistor T69, and a third capacitor Cs3.

A gate electrode of the eighth light-emission control transistor T68 iscoupled to the first light-emission control node EC1, a first electrodeof the eighth light-emission control transistor T68 is coupled to thehigh level output end for outputting the high level VGH, and a secondelectrode of the eighth light-emission control transistor T68 is coupledto the second light-emission control node EC2.

A gate electrode of the ninth light-emission control transistor T69 iscoupled to the first clock signal output end CK1, a first electrode ofthe ninth light-emission control transistor T69 is coupled to a secondlight-emission control node EC2, and a second electrode of the ninthlight-emission control transistor T69 is coupled to the low level outputend for outputting the low level VGL.

A first end of the third capacitor Cs3 is coupled to the secondlight-emission control node EC2, and a second end of the third capacitorCs3 is coupled to the second clock signal output end CK2.

The light-emission control signal generation circuit includes: a firstlight-emission control signal generation transistor T610, and a secondlight-emission control signal generation transistor T611.

A gate electrode of the first light-emission control signal generationtransistor T610 is coupled to the first light-emission control node EC1,a first electrode of the first light-emission control signal generationtransistor T610 is coupled to the high level output end for outputtingthe high level VGH, and a second electrode of the first light-emissioncontrol signal generation transistor T610 is coupled to thelight-emission control signal output EMOUT.

A gate electrode of the second light-emission control signal generationtransistor T611 is coupled to the second light-emission control nodeEC2, a first electrode of the second light-emission control signalgeneration transistor T611 is coupled to the light-emission controlsignal output end EMOUT, and a second electrode of the secondlight-emission control signal generation transistor T611 is coupled tothe voltage signal output end for outputting the voltage signal VGL-1.

As shown in FIG. 7, the display stage for the pixel in a correspondingrow may include four stages, i.e., TS2, TE, T73 and T74.

At the second start stage TS2, VGL-1 is a low level, STV2 inputs a lowlevel, CK1 outputs a low level, and CK2 outputs a high level, so T61 andT63 are turned on. VGL is written into the gate electrode of T64, andSTV2 is coupled to the gate electrode of T65, so T64 and T65 are turnedon, and the potential of EC1 is at a high level. T69 is turned on, sothe potential of EC2 is at a low level. T610 is turned off and T611 isturned on, so EMOUT receives VGL-1 and outputs a low level.

At the light-emission stage TE, VGL-1 is a low level, STV2 inputs a highlevel, CK1 outputs a high level, and CK2 outputs a low level, so T61,T63 and T69 are turned on. The potential of the gate electrode of T65 ismaintained at a low level, T65 is turned on, and EC1 is coupled to CK1,so the potential of EC1 is at a low level. T68 is turned on, so EC2receives VGH. T611 is turned off, and T610 is turned on, so EMOUToutputs the high level VGH.

At the third stage T73, VGL-1 is a low level, STV2 inputs a high level,CK1 outputs a low level, and CK2 outputs a high level, so T61 and T63are turned on. VGL is written into the gate electrode of T64, STV2 iscoupled to the gate electrode of T65, and the potential of the gateelectrode of T65 is a high level, so T64 is turned on and T65 is turnedoff. The potential of EC1 is at a high level. T69 is turned on, so thepotential of EC2 is a low level. T610 is turned on, and T611 is turnedon, so EMOUT receives VGL-1 and outputs a low level.

At the fourth stage T74, VGL-1 is a low level, STV2 inputs a high level,CK1 outputs a high level and CK2 outputs a low level, so T61, T63 andT69 are turned off and the potential of GO is maintained as a highlevel. Because CK2 outputs a low level, T610 is turned off, and EC2 ispulled down by Cs3 to a potential lower than the potential of T73. T611is turned on, so EMOUT receives VGL-1 and outputs a low level.

At the fingerprint detection stage TF, VGL-1 is a square-wave voltagesignal, STV2 inputs a high level, CK1 outputs a low level and CK2outputs a high level, so T61, T63 and T69 are turned on. VGL is writteninto the gate electrode of T64, STV2 is coupled to the gate electrode ofT65, and the potential of the gate electrode of T65 is at a high level,so T64 is turned on, T65 is turned off, and the potential of EC1 is at ahigh level. T69 is turned on, so the potential of EC2 is at a low level.T610 is turned off, and T611 is turned on, so EMOUT receives VGL-1 andoutputs a square-wave voltage signal. In other words, at the fingerprintdetection stage, the fingerprint detection light-emission control signaloutputted by EMOUT is a square-wave light-emission control signal whichhas a frequency greater than 1000 Hz.

As shown in FIG. 7, at the fingerprint detection stage TF, VGL-1 is thesquare-wave voltage signal, and EM outputs the square-wave voltagesignal, so a requirement on outputting the light-emission control signalmay be met.

During the implementation, the photovoltaic conversion element mayinclude a photo diode. An anode of the photo diode is coupled to a fixedelectrically-conductive electrode, and a cathode of the photo diode iscoupled to the fingerprint current read line.

As shown in FIG. 8, a photosensitive PIN junction is arranged betweentwo adjacent pixels. The pixels in each row are coupled to the samelight-emission control line, and the photosensitive PIN junctions ineach column are coupled to the same fingerprint current read line.Through supplying the light-emission control signal row by row, thefingerprint current read line may receive a PIN optical response signalwith respect to the light from the pixels in the same row. Then, thereceived PIN optical response signal may be demodulated through an IC inaccordance with a modulation frequency (which may be a modulationfrequency of VGH-A at the fingerprint detection stage TF), so as toacquire an electric signal containing fingerprint information. Thefingerprint information in a Y-axis direction may be determined throughthe scanning operation on the light-emission control line, and thefingerprint information in an X-axis direction may be determined inaccordance with the information from the fingerprint current read line.The modulation operation is used mainly for the reason that thedemodulated signal merely reflects the information about the modulatedsignal and the detection result may not be adversely affected by lightfrom the pixels in other rows.

In FIG. 8, EM1 represents a first light-emission control line, EMmrepresents an m^(th) light-emission control line, RL1 represents a firstfingerprint current read line, RLn represents an n^(th) fingerprintcurrent read line, where m and n are each a positive integer. Thephotosensitive PIN junctions in one column are coupled to the samefingerprint current read line, and the pixels in one row are coupled tothe same light-emission control line.

In practice, as shown in FIG. 9, four pixels are arranged adjacent toeach other on a back glass substrate 90. A first pixel includes fromleft to right a first red subpixel R1, a first green subpixel G1 and afirst blue subpixel B1. A second pixel includes from left to right asecond red subpixel R2, a second green subpixel G2 and a second bluesubpixel B2. A third pixel includes from left to right a third redsubpixel R3, a third green subpixel G3 and a third blue subpixel B3. Afourth pixel includes from left to right a fourth red subpixel R4, afourth green subpixel G4 and a fourth blue subpixel B4.

A fixed electrode 91 made of indium tin oxide (ITO) is arranged on aglass encapsulation substrate 92, and an insulation layer is arrangedbetween the fixed electrode 91 and the back glass substrate 90. In theembodiments of the present disclosure, the photosensitive PIN junctionis formed on the glass encapsulation substrate 92, at a positioncorresponding to a non-light-emission region and between two adjacentpixels. An anode of each photosensitive PIN junction is coupled to thefixed electrode 91, and a cathode of each photosensitive PIN junction iscoupled to a corresponding fingerprint current read line. In FIG. 9,PIN1 represents a first photosensitive PIN junction, PIN2 represents asecond photosensitive PIN junction, and PIN3 represents a thirdphotosensitive PIN junction.

In FIG. 9, the light from each pixel is reflected by a finger toward thephotosensitive PIN junction. At the fingerprint detection stage, theremay be a difference between intensities of the light reflected fromvalleys and ridges of the fingerprint to the photosensitive PINjunctions, and thereby the currents read by the fingerprint current readline may differ from each other. In this way, it is possible to detectthe valleys and ridges of the fingerprint (optionally, eachphotosensitive PIN junction may be in a reverse bias state).

The present disclosure further provides in some embodiments a method ofdriving the above-mentioned display driving unit circuit, whichincludes: supplying, by the light-emission control signal generationcircuit, a display light-emission control signal to the pixel drivingcircuit at the display stage; and supplying, by the light-emissioncontrol signal generation circuit, a fingerprint detectionlight-emission control signal to the pixel driving circuit at thefingerprint detection stage to control the pixel driving circuit at thefingerprint detection stage to enable the pixel to emit light in afingerprint detection light-emission mode. The display stage and thefingerprint detection stage are different time periods.

According to the driving method in the embodiments of the presentdisclosure, it is possible to supply the fingerprint detectionlight-emission control signal to the corresponding pixel driving circuitthrough the light-emission control signal generation circuit at thefingerprint detection stage, and output the photocurrent signal throughthe photovoltaic conversion element at the fingerprint detection stage,so as perform the fingerprint detection.

In a possible embodiment of the present disclosure, the fingerprintdetection light-emission control signal is a square-wave light-emissioncontrol signal having a frequency greater than 1000 Hz. In this way, thelight from the pixel in the corresponding row may not be perceived bythe human eyes at the fingerprint detection stage, so as to prevent thenormal display effect from being adversely affected. In addition, at thefingerprint detection stage, the optical signal from each pixel is asquare-wave modulated optical signal, the photovoltaic conversionelement may convert the square-wave modulated optical signal into asquare-wave modulated fingerprint current, so it is able todifferentiate the current acquired through the conversion ofphotovoltaic conversion element from a fingerprint current. A cycle ofthe square-wave light-emission control signal includes a first timeperiod in which the pixel driving circuit controls the pixel to emitlight under the control of the square-wave light-emission control signaland a second time period in which the pixel driving circuit controls thepixel not to emit light under the control of the square-wavelight-emission control signal.

The present disclosure provides in some embodiments a display drivingcircuit including a plurality of light-emission control lines and aplurality of the above-mentioned display driving unit circuits. Eachlight-emission control line is coupled to a light-emission controlsignal output end of one pixel driving circuit of the plurality ofdisplay driving unit circuits, display stages for pixels in differentrows do not overlap each other, and fingerprint detection stages for thepixels in different rows do not overlap each other.

In implementations, the fingerprint detection stages for the pixels indifferent rows do not overlap each other. In this way, it is possiblefor the IC to determine the light-emission control line to which a touchposition corresponds.

In practice, the light-emission control signal generation circuits ofall the display driving unit circuits of the display driving circuit arecontained in a light-emission GOA circuit (EM-GOA), which is configuredto transmit a modulated light-emission control signal to the pluralityof light-emission control lines. Because the modulated light-emissioncontrol signal has a high frequency at the fingerprint detection stage,the light emitted by the pixel in the corresponding row may not beperceived by human eyes, and thus the normal display effect may not beadversely affected.

In the embodiments of the present disclosure, the display drivingcircuit further includes a voltage signal generation GOA circuit(VGL-GOA) which includes a plurality of voltage signal generationcircuits each configured to supply a voltage signal VGL-1 to thecorresponding light-emission control signal generation circuit, so as toenable the OLED pixels to emit light row by row.

The display driving circuit in the embodiments of the present disclosureis based on the EM-GOA with an Active Matrix Organic Light-EmittingDiode (AMOELD) structure. At the fingerprint detection stage, the OLEDpixel generates modulated light under the control of the light-emissioncontrol signal. In addition, the display driving circuit furtherincludes the light-emission control GOA circuit and the voltage signalgeneration GOA circuit (VGL-GOA), so as to supply the modulatedlight-emission control signal sequentially to each row of pixels, so thenormal display effect may substantially not be adversely affected.Further, the photosensitive array design is different from aconventional design, and the display driving circuit in the embodimentsof the present disclosure is provided with the photosensitive arrayrather than any switching array.

The present disclosure provides in some embodiments a display deviceincluding the above-mentioned display driving circuit and photovoltaicconversion elements each of which is arranged at a positioncorresponding to a non-light-emission region, coupled to a fingerprintcurrent read line, and configured to convert a received optical signalinto a fingerprint current signal outputted via the fingerprint currentread line.

The above are merely optional embodiments of the present disclosure. Aperson skilled in the art may make modifications and improvements tothose embodiments without departing from the principle of the presentdisclosure, and these modifications and improvements shall also fallwithin the scope of the present disclosure.

What is claimed is:
 1. A display driving unit circuit, comprising: apixel driving circuit and a light-emission control signal generationcircuit; wherein the light-emission control signal generation circuit iscoupled to the pixel driving circuit; the pixel driving circuit isconfigured to drive a pixel to emit light; the light-emission controlsignal generation circuit is configured to supply a displaylight-emission control signal to the pixel driving circuit at a displaystage to enable the pixel in a displaying mode and supply a fingerprintdetection light-emission control signal to the pixel driving circuit ata fingerprint detection stage to enable the pixel in a fingerprintdetection light-emission mode; and wherein the display stage and thefingerprint detection stage are different time periods.
 2. The displaydriving unit circuit according to claim 1, wherein light emitted fromthe pixel in the displaying mode is of a first frequency, light emittedfrom the pixel in the fingerprint detection light-emission mode is of asecond frequency, and the first frequency is different from the secondfrequency.
 3. The display driving unit circuit according to claim 2,wherein the fingerprint detection light-emission control signal is asquare-wave light-emission control signal having a frequency equal tothe second frequency; a cycle of the square-wave light-emission controlsignal comprises a first time period in which the pixel driving circuitcontrols the pixel to emit light having a frequency equal to the firstfrequency under the control of the square-wave light-emission controlsignal and a second time period in which the pixel driving circuitcontrols the pixel to emit light having a frequency equal to the secondfrequency under the control of the square-wave light-emission controlsignal.
 4. The display driving unit circuit according to claim 3,wherein the first frequency is substantially equal to 0 Hz, and thesecond frequency is greater than 1000 Hz.
 5. The display driving unitcircuit according to claim 1, further comprising a voltage signalgeneration circuit; wherein the voltage signal generation circuit iscoupled to the light-emission control signal generation circuit and isconfigured to supply the fingerprint detection light-emission controlsignal to a light-emission control signal output end of thelight-emission control signal generation circuit at the fingerprintdetection stage.
 6. The display driving unit circuit according to claim5, wherein the voltage signal generation circuit includes a first startsignal input end, a first clock signal output end, a second clock signaloutput end, a first level output end, a second level output end, a thirdlevel output end and a voltage signal output end, wherein the voltagesignal generation circuit further includes: a first voltage control nodecontrol circuit that is coupled to the first start signal input end, thefirst clock signal output end, the second clock signal output end, thefirst level output end, the second level output end and a first voltagecontrol node, and is configured to enable a potential of the firstvoltage control node to be a first level and enable the potential of thefirst voltage control node to be a second level at the fingerprintdetection stage under the control of the first start signal input end,the first clock signal output end, the second clock signal output end,the first level output end, the second level output end; a secondvoltage control node control circuit that is coupled to the firstvoltage control node, the first clock signal output end, the secondclock signal output end, the first level output end, the second leveloutput end and a second voltage control node, and is configured toenable a potential of the second voltage control node to be the secondlevel and enable the potential of the second voltage control node to bethe first level at the fingerprint detection stage under the control ofthe first voltage control node, the first clock signal output end, thesecond clock signal output end, the first level output end and thesecond level output end; and a voltage signal generation circuit that iscoupled to the first voltage control node, the second voltage controlnode, the third level output end, the second level output end and avoltage signal output end, and is configured to enable the voltagesignal output end to receive a signal from the second level output endunder the control of the second voltage control node, and enable thevoltage signal output end to receive a signal from the third leveloutput end under the control of the first voltage control node at thefingerprint detection stage to enable the voltage signal output end tooutput the fingerprint detection light-emission control signal at thefingerprint detection stage.
 7. The display driving unit circuitaccording to claim 6, wherein the first voltage control node controlcircuit includes: a first voltage control transistor, a second voltagecontrol transistor, a third voltage control transistor, a fourth voltagecontrol transistor, a fifth voltage control transistor, a sixth voltagecontrol transistor, a seventh voltage control transistor, a firststorage capacitor and a second storage capacitor; wherein a gateelectrode of the first voltage control transistor is coupled to thefirst clock signal output end, and a first electrode of the firstvoltage control transistor is coupled to the first start signal inputend; wherein a gate electrode of the second voltage control transistoris coupled to a second electrode of the first voltage controltransistor, and a second electrode of the second voltage controltransistor is coupled to the first clock signal output end; wherein agate electrode of the third voltage control transistor is coupled to thefirst clock signal output end, a first electrode of the third voltagecontrol transistor is coupled to a first electrode of the second voltagecontrol transistor, and a second electrode of the third voltage controltransistor is coupled to a low level output end; wherein a gateelectrode of the fourth voltage control transistor is coupled to thefirst electrode of the third voltage control transistor, a firstelectrode of the fourth voltage control transistor is coupled to a highlevel output end, and a second electrode of the fourth voltage controltransistor is coupled to the first voltage control node; wherein a gateelectrode of the fifth voltage control transistor is coupled to thesecond electrode of the first voltage control transistor, a firstelectrode of the fifth voltage control transistor is coupled to thefirst voltage control node, and a second electrode of the fifth voltagecontrol transistor is coupled to the second clock signal input end;wherein a gate electrode of the sixth voltage control transistor iscoupled to the gate electrode of the fourth voltage control transistor,and a first electrode of the sixth voltage control transistor is coupledto the high level output end; wherein a gate electrode of the seventhvoltage control transistor is coupled to the second clock signal outputend, a first electrode of the seventh voltage control transistor iscoupled to a second electrode of the sixth voltage control transistor,and a second electrode of the seventh voltage control transistor iscoupled to the gate electrode of the fifth voltage control transistor;wherein a first end of the first storage capacitor is coupled to thegate electrode of the fifth voltage control transistor, and a second endof the first storage capacitor is coupled to the first voltage controlnode; and wherein a first end of the second storage capacitor is coupledto the gate electrode of the fourth voltage control transistor, and asecond end of the second storage capacitor is coupled to the high leveloutput end.
 8. The display driving unit circuit according to claim 7,wherein the second voltage control node control circuit includes: aneighth voltage control transistor, a ninth voltage control transistorand a third storage capacitor; wherein a gate electrode of the eighthvoltage control transistor is coupled to the first voltage control node,a first electrode of the eighth voltage control transistor is coupled tothe high level output end, and a second electrode of the eighth voltagecontrol transistor is coupled to the second voltage control node;wherein a gate electrode of the ninth voltage control transistor iscoupled to the first clock signal output end, a first electrode of theninth voltage control transistor is coupled to the second voltagecontrol node, and a second electrode of the ninth voltage controltransistor is coupled to the low level output end; and wherein a firstend of the third storage capacitor is coupled to the second voltagecontrol node, and a second end of the third storage capacitor is coupledto the second clock signal output end.
 9. The display driving unitcircuit according to claim 8, wherein the voltage signal generationcircuit includes: a first voltage signal generation transistor and asecond voltage signal generation transistor; wherein a gate electrode ofthe first voltage signal generation transistor is coupled to the firstvoltage control node, a first electrode of the first voltage signalgeneration transistor is coupled to a square-wave voltage signal outputend, and a second electrode of the first voltage signal generationtransistor is coupled to the voltage signal output end; and wherein agate electrode of the second voltage signal generation transistor iscoupled to the second voltage control node, a first electrode of thesecond voltage signal generation transistor is coupled to the voltagesignal output end, and a second electrode of the second voltage signalgeneration transistor is coupled to the low level output end.
 10. Thedisplay driving unit circuit according to claim 1, wherein thelight-emission control signal generation circuit includes a second startsignal input end, a first clock signal output end, a second clock signaloutput end, a first level output end, a second level output end, avoltage signal output end and a light-emission control signal outputend; wherein the light-emission control signal generation circuitfurther includes: a first light-emission control node control circuitthat is coupled to the second start signal input end, the first clocksignal output end, the second clock signal output end, the first leveloutput end, the second level output end and a first light-emissioncontrol node, and is configured to enable a potential of the firstlight-emission control node to be a first level at the fingerprintdetection stage and enable the potential of the first light-emissioncontrol node to be a second level at a light-emission stage under thecontrol of the second start signal input end, the first clock signaloutput end, the second clock signal output end, the first level outputend and the second level output end; a second light-emission controlnode control circuit that is coupled to the first light-emission controlnode, the first clock signal output end, the second clock signal outputend, the first level output end, the second level output end and asecond light-emission control node, and is configured to enable apotential of the second light-emission control node to be the secondlevel at the fingerprint detection stage and enable the potential of thesecond light-emission control node to be the first level at thelight-emission stage under the control of the first light-emissioncontrol node, the first clock signal output end, the second clock signaloutput end, the first level output end and the second level output end;and a light-emission control signal generation circuit that is coupledto the first light-emission control node, the second light-emissioncontrol node, the first level output end, the voltage signal output endand the light-emission control signal output end, and is configured toenable the light-emission control signal output end to receive a signalfrom the first level output end under the control of the firstlight-emission control node at the light-emission stage, and enable thelight-emission control signal output end to receive a signal from thevoltage signal output end under the control of the second light-emissioncontrol node at the fingerprint detection stage to enable thelight-emission control signal output end to output the fingerprintdetection light-emission control signal at the fingerprint detectionstage.
 11. The display driving unit circuit according to claim 10,wherein the first light-emission control node control circuit includes:a first light-emission control transistor, a second light-emissioncontrol transistor, a third light-emission control transistor, a fourthlight-emission control transistor, a fifth light-emission controltransistor, a sixth light-emission control transistor, a seventhlight-emission control transistor, a first capacitor and a secondcapacitor; wherein a gate electrode of the first light-emission controltransistor is coupled to the first clock signal output end, and a firstelectrode of the first light-emission control transistor is coupled tothe second start signal input end; wherein a gate electrode of thesecond light-emission control transistor is coupled to a secondelectrode of the first light-emission control transistor, and a secondelectrode of the second light-emission control transistor is coupled tothe first clock signal output end; wherein a gate electrode of the thirdlight-emission control transistor is coupled to the first clock signaloutput end, a first electrode of the third light-emission controltransistor is coupled to a first electrode of the second light-emissioncontrol transistor, and a second electrode of the third light-emissioncontrol transistor is coupled to the low level output end; wherein agate electrode of the fourth light-emission control transistor iscoupled to the first electrode of the third light-emission controltransistor, a first electrode of the fourth light-emission controltransistor is coupled to the high level output end, and a secondelectrode of the fourth light-emission control transistor is coupled toa first light-emission control node; wherein a gate electrode of thefifth light-emission control transistor is coupled to the secondelectrode of the first light-emission control transistor, a firstelectrode of the fifth light-emission control transistor is coupled tothe first light-emission control node, and a second electrode of thefifth light-emission control transistor is coupled to the second clocksignal output end; wherein a gate electrode of the sixth light-emissioncontrol transistor is coupled to the gate electrode of the fourthlight-emission control transistor, and a first electrode of the sixthlight-emission control transistor is coupled to the high level outputend; wherein a gate electrode of the seventh light-emission controltransistor is coupled to the second clock signal output end, a firstelectrode of the seventh light-emission control transistor is coupled toa second electrode of the sixth light-emission control transistor, and asecond electrode of the seventh light-emission control transistor iscoupled to the gate electrode of the fifth light-emission controltransistor; wherein a first end of the first capacitor is coupled to thegate electrode of the fifth light-emission control transistor, and asecond end of the first capacitor is coupled to the first light-emissioncontrol node; and wherein a first end of the second capacitor is coupledto the gate electrode of the fourth light-emission control transistor,and a second end of the second capacitor is coupled to the high leveloutput end.
 12. The display driving unit circuit according to claim 11,wherein the second light-emission control node control circuit includes:an eighth light-emission control transistor, a ninth light-emissioncontrol transistor and a third capacitor; wherein a gate electrode ofthe eighth light-emission control transistor is coupled to the firstlight-emission control node, a first electrode of the eighthlight-emission control transistor is coupled to the high level outputend, and a second electrode of the eighth light-emission controltransistor is coupled to the second light-emission control node; whereina gate electrode of the ninth light-emission control transistor iscoupled to the first clock signal output end, a first electrode of theninth light-emission control transistor is coupled to a secondlight-emission control node, and a second electrode of the ninthlight-emission control transistor is coupled to the low level outputend; and wherein a first end of the third capacitor is coupled to thesecond light-emission control node, and a second end of the thirdcapacitor is coupled to the second clock signal output end.
 13. Thedisplay driving unit circuit according to claim 12, wherein thelight-emission control signal generation circuit includes: a firstlight-emission control signal generation transistor and a secondlight-emission control signal generation transistor; wherein a gateelectrode of the first light-emission control signal generationtransistor is coupled to the first light-emission control node, a firstelectrode of the first light-emission control signal generationtransistor is coupled to the high level output end, and a secondelectrode of the first light-emission control signal generationtransistor is coupled to the light-emission control signal output; andwherein a gate electrode of the second light-emission control signalgeneration transistor is coupled to the second light-emission controlnode, a first electrode of the second light-emission control signalgeneration transistor is coupled to the light-emission control signaloutput end, and a second electrode of the second light-emission controlsignal generation transistor is coupled to the voltage signal outputend.
 14. The display driving unit circuit according to claim 1, whereinthe pixel driving circuit includes: a first transistor, a secondtransistor, a third transistor, a fourth transistor, a fifth transistor,a sixth transistor and a storage capacitor; wherein a gate electrode ofthe first transistor is coupled to a resetting end, a source electrodeof the first transistor is coupled to a resetting voltage signal inputend, and a drain electrode of the first transistor is coupled to a firstend of the storage capacitor; wherein a gate electrode of the secondtransistor is coupled to a corresponding gate line, and a sourceelectrode of the second transistor is coupled to the first end of thestorage capacitor; wherein a gate electrode of the third transistor iscoupled to the first end of the storage capacitor, and a sourceelectrode of the third transistor is coupled to a drain electrode of thesecond transistor; wherein a gate electrode of the fourth transistor iscoupled to a corresponding gate line, a source electrode of the fourthtransistor is coupled to a corresponding data line, and a drainelectrode of the fourth transistor is coupled to a second end of thestorage capacitor; wherein a gate electrode of the fifth transistor iscoupled to a control signal input end, and a source electrode of thefifth transistor is coupled to the second end of the storage capacitor;and wherein a gate electrode of the sixth transistor is coupled to thelight-emission control signal input end, a source electrode of the sixthtransistor is coupled to an anode of an organic light-emitting diode,and a drain electrode of the sixth transistor is coupled to the sourceelectrode of the third transistor.
 15. A method of driving a displaydriving unit circuit, the display driving unit circuit comprising apixel driving circuit and a light-emission control signal generationcircuit, the light-emission control signal generation circuit beingcoupled to the pixel driving circuit, the pixel driving circuit beingconfigured to drive a pixel to emit light, the light-emission controlsignal generation circuit being configured to supply a displaylight-emission control signal to the pixel driving circuit at a displaystage to enable the pixel in a displaying mode and supply a fingerprintdetection light-emission control signal to the pixel driving circuit ata fingerprint detection stage to enable the pixel in a fingerprintdetection light-emission mode, and the display stage and the fingerprintdetection stage being different time periods; wherein the methodcomprises: supplying, by a light-emission control signal generationcircuit, a display light-emission control signal to a pixel drivingcircuit at a display stage to enable a pixel in the displaying mode; andsupplying, by the light-emission control signal generation circuit, afingerprint detection light-emission control signal to the pixel drivingcircuit at a fingerprint detection stage to control the pixel drivingcircuit at the fingerprint detection stage to enable the pixel in afingerprint detection light-emission mode.
 16. The method according toclaim 15, wherein the fingerprint detection light-emission controlsignal is a square-wave light-emission control signal having a frequencygreater than 1000 Hz; and a cycle of the square-wave light-emissioncontrol signal includes a first time period in which the pixel drivingcircuit controls the pixel to emit light having a frequency equal to 0Hz under the control of the square-wave light-emission control signaland a second time period in which the pixel driving circuit controls thepixel to emit light having a frequency greater than 1000 Hz under thecontrol of the square-wave light-emission control signal.
 17. A displaydriving circuit comprising: a plurality of light-emission control linesand a plurality of display driving unit circuits; wherein each of theplurality of display driving unit circuit includes a pixel drivingcircuit and a light-emission control signal generation circuit; whereinthe light-emission control signal generation circuit is coupled to alight-emission control signal input end of the pixel driving circuit andis configured to supply a display light-emission control signal to thepixel driving circuit at a display stage to enable a pixel in adisplaying mode and supply a fingerprint detection light-emissioncontrol signal to the pixel driving circuit at a fingerprint detectionstage to enable the pixel in a fingerprint detection light-emission modeat the fingerprint detection stage; each of the plurality oflight-emission control lines is coupled to a light-emission controlsignal output end of one pixel driving circuit of the plurality ofdisplay driving unit circuits, and display stages for different rows ofpixels do not overlap each other, and fingerprint detection stages fordifferent rows of pixels do not overlap each other.
 18. A displaydevice, comprising: photovoltaic conversion elements and the displaydriving circuit according to claim 17; wherein each of the photovoltaicconversion elements is at a position corresponding to anon-light-emission region, coupled to a fingerprint current read line,and configured to convert a received optical signal into a fingerprintcurrent signal and output the fingerprint current signal via thefingerprint current read line.
 19. The display device according to claim18, wherein each of the photovoltaic conversion elements is between twoadjacent pixels in a row direction.
 20. The display device according toclaim 18, wherein each photovoltaic conversion element includes a photodiode having an anode coupled to a fixed electrically-conductiveelectrode and a cathode coupled to the fingerprint current read line.